Received a replacement few days ago from the second wave of production.
So far works like a charm, no single boot issue detected!
The problem of quiet sound from the headphones port also seems to be fixed.

Thanks, Pierre, for all the effort you've put to resolve that crappy situation, you didn't give up despite of all hate from some too angry backers!

I always thought the boot problem is a software issue. Tried to apply the fix now but I still get a lot of blackscreens. Actually I get more bad boots than normal ones. Also tried 3 different micro SD cards. Using Supreme Retrostone 1.3.

Hi,
On your picture I am not sure what has been done on the pcb as it's a bit black.

Can you give me some details on what you have done there?

Is there conductivity between the ground plane and the microSD case? Meaning is there solder touching both the pins of the resistor (connecting them electrically).

If you have just removed the resistor but without replacing it with solder then it's normal that you have even more fail boot.

If you have a multimeter you can use it as ohmmeter to check if you have 0 ohm between ground (you can get GND on some pins on the board) and the SD metal case. If you don't read 0 ohm then it's not good.

Hello,
when I soldered it, there was enough solder that touched both the pins. Didn't remove the resistor but it definitely wasn't black when I soldered it.
I still played with the Retrostone and it kind of looks the solder spread from the resistor.
Sorry I don't own a multimeter so I can't check.